Determination of Water Content of Water-soluble Paints by Gas Chromatography

This paper describes the determination of water content of water-soluble paints by gas chromatography. The water in paints is extracted by dimethyl formamide (DMF) as a solvent.Isopropanol is used as an internal standard. The mixture is separated by low-speed centrifugation.Then a 1-uL sample of the supernatant from the prepared solution is injected into the gas chromatograph. The water content is determined by internal standard calibration curve. The rate of recovery of added standard of this method is more than 98%. Relative mean deviation is less than 3‰.The linearity of calibration curve is good and relativity coefficient is higher than 0.998.

水性涂料中水含量的测定

采用气相色谱法测定亲水性涂料中的水分含量。涂料试样以二甲基甲酰胺 (DMF)为溶剂 ,萃取出其中的水分 ,以异丙醇为内标物 ,经离心分离后 ,取上层清液注射入气相色谱仪 ,用内标标准曲线法 ,测定涂料中的水含量。该方法的加标回收率大于 98% ,相对平均偏差小于 0 .3 % ,内标标准曲线线性良好 ,其相关系数均大于 0 998。